Transfer of values UpdateSetpoint

[lschib01]

I work with a SFC6000D via I2C with a RPi 5 and Python 3.11. I think there is a problem with the transfer of values in the UpdateSetpoint function.

The processing of the input values of update_setpoint fails with t.pack() in transfer.py. A pointer address is passed here instead of the value. I'm not sure if this is the case for all functions in which a value is passed to the controller. However, I have not checked this. All functions without value transfer work perfectly.

I have implemented the following solution, but it is not ideal as it does not solve the actual problem but deals with the symptoms. The pack() function is defined in rx_tx_data.py. Here I enter the further processing of the value (update_setpoint), which is passed as arg in argument_list[]. If the CMD_ID = 0xf054 (UpdateSetpoint), arg = arg.value is set. This ensures that the value and not the address is passed.

If I output the argument_list[] without the customisation, the output looks like this:
<sensirion_i2c_sfx6xxx.result_types.SignalRawFlow object at 0x7ffebff2d150>

After the adjustment, the value is output instead of the address. (e.g. as rawFlow = -18381)

def pack(self, argument_list=[]):
data_to_pack = [self._cmd_id]
for arg in argument_list:
if self._cmd_id == 0xf054:
arg = arg.value
if isinstance(arg, str):
data_to_pack.append(self._string_to_bytes(arg))
elif isinstance(arg, (list, tuple)):
data_to_pack.extend(arg)
else:
data_to_pack.append(arg)

[psachs]

I think the problem, is that it is not clear how to work with the returned signals from the driver.

As you already figured out, you get the a SignalRawFlow when you do a measurement. If you want to use this signal as a setpoint you have to provide the .value and not the whole signal.
Here is some pseudo code on what I refer to.

sfc6000 = Sfx6xxxDevice(channel)
flow = sfc6000.read_flow()
sfc6000.update_setpoint(flow.value)

I am also not sure if I understand your problem correctly. I don't think you want to set the set_point to the measured flow since the set point controls the flow, resp. the measured flow should follow the configured setpoint.

[psachs]

Hi I just had some more time looking into the issue and opened a pull request that should hopefully fix the issue with update setpoint and another issue with reading the product identifier.

I hope I can release a bugfix version tomorrow